The present invention relates to an apparatus configured to simulate the directional and parallelity aspects of sunlight falling on a three dimensional model for any specified combination of latitude, time of day, and day of the year.
Heliodons were originally configured to be operated indoors using an artificial light source to simulate the effect of sunlight falling on a model. Subsequent heliodon designs were developed that used the sun as the source of light. Heliodons of the second type enable the model to be positioned relative to the sun for a specified day, time, and latitude. The heliodon is operated by adjusting and holding the apparatus to the desired day and time as indicated on a shade dial. The shade dial is set to the desired latitude and mounted on the model. A similar method includes mounting a sundial onto the model and subsequently mounting the model onto a tripod. The mounted sundial is set to the desired latitude. The desired simulated day(s) and time(s) for casting sunlight onto the building model are obtained by manipulating and fixing the components of the tripod, such that sunlight falling onto the sundial indicates the desired day and time.
The invention provides an apparatus for use with a source of light, the apparatus comprising a first orientation device including a latitude scale, a latitude pointer rotatable about a first axis relative to the latitude scale, and a platform configured to support an architectural model. The platform is mounted on the latitude pointer such that rotation of the pointer about the first axis produces a corresponding change in the position of the platform relative to the latitude scale.
The apparatus also includes a second orientation device that includes a time scale and a time pointer rotatable about a second axis relative to the time scale. The first orientation device is mounted on the time pointer such that rotation of the time pointer about the second axis produces a corresponding change in the position of the platform relative to the time scale without changing the position of the platform relative to the latitude scale.
The apparatus further includes a third orientation device that includes a day of the year scale, a gnomon operatively oriented relative to the day of the year scale, and a universal joint supporting the third orientation device for movement relative to a source of light.
The second orientation device is mounted on the third orientation device such that movement of the third orientation device on the universal joint produces a corresponding change in the position of the platform relative to the source of light without changing the position of the time pointer relative to the time scale or the position of the platform relative to the latitude scale.